18438641 has 8 divisors (see below), whose sum is σ = 19962600. Its totient is φ = 16929792.

The previous prime is 18438619. The next prime is 18438649. The reversal of 18438641 is 14683481.

It can be written as a sum of positive squares in 4 ways, for example, as 461041 + 17977600 = 679^2 + 4240^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18438641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18438649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1166 + ... + 6183.

It is an arithmetic number, because the mean of its divisors is an integer number (2495325).

Almost surely, 2^18438641 is an apocalyptic number.

It is an amenable number.

18438641 is a deficient number, since it is larger than the sum of its proper divisors (1523959).

18438641 is a wasteful number, since it uses less digits than its factorization.

18438641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7555.

The product of its digits is 18432, while the sum is 35.

The square root of 18438641 is about 4294.0238704507. The cubic root of 18438641 is about 264.1859007823.

The spelling of 18438641 in words is "eighteen million, four hundred thirty-eight thousand, six hundred forty-one".